AS the modern technology progresses, the Internet has became more indispensable to people. A transmission of a huge amount of digital information through a network will easily cause the congestion collapse problem, which leads to stop working and serious damages.
Transmission Control Protocol (TCP), for example, is used extensively by many of the internet's most popular application protocols. In the TCP's congestion control mechanism, a TCP sender transmits a packet, and then starts a retransmission timer to clock the round-trip time (RTT) of the packet so as to ensure that the packet will be successfully transmitted. When a TCP receiver successfully receives the packet, it will transmit an acknowledgment (ACK) of the packet to the TCP sender to acknowledge receipt of a packet. The mechanism attempts to avoid the congestion collapse problem and to make the transmission smooth.
If the network causes the delay of the packet transmission to make RTT longer than retransmission timeout (RTO), the TCP sender will consider the situation as “packet loss”, and then retransmit the packet and restart the retransmission timer. If the TCP sender receives the ACK within the RTO, the retransmission timer clocking the RTT of the packet will stop and restart clocking when the next packet is transmitted.
The TCP's congestion control mechanism uses a timer to prevent the packet loss problem and to avoid congestion collapse problem. However, there is still a possibility which makes the network congested. If the network load is heavy, the delay of the packet transmission will increase and the RTT of the packet will also increase. As a result, the TCP sender retransmits the packet, which will lead to more retransmissions. The procedure is repeated and the network load becomes more and more heavy. Finally, the network may become congested and blocked, and the transmission is collapsed.
Accordingly, a method for a network transmission to solve the above problems is developed. The inventors purpose to rectify those drawbacks and provide the method for the network transmission that adjusts retransmission timer with the fuzzy rule to make the RTO change with network traffic. The method not only minimizes retransmission and lost packets but also keeps utilization higher. The method is used to solve the congestion collapse problem in network transmission.